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Roundabouts: The first choice for traffic safety and control

Unfamiliar to some drivers, roundabouts are a safe, sustainable, and affordable choice to keep communities moving

I am a staunch promoter of the use of roundabouts. Why? Because roundabouts offer a safe, more efficient, environmentally friendly, and cost-effective form of traffic control. It’s that simple. For those not familiar with the terminology, a roundabout is an intersection with a circular traffic flow pattern, where drivers enter the intersection and travel around a center island without the use of traffic signals or stop signs.

I have made it my goal to encourage municipalities to adopt a policy of “roundabouts first,” considering roundabouts as the primary option for intersection improvements. Here’s the case I make.

Safety

What really got me interested in roundabouts was the safety aspect, and that is their most important feature, by far. They are good for people because they are generally safer than traditional intersections. Roundabouts are developing a track record across North America for providing better safety at intersections. There was a study done in the late 1990s by the Insurance Institute in the States, documenting collision reductions. What really got my attention was the 90 to 95 per cent reduction in fatal collisions.

Any time that you can reduce road fatalities strikes home. As a transportation engineer, making our roads as safe as possible through geometric design, through operations and controls, is what we do; it's why we got into this business. Moving people, and moving goods, is so important. But to do it safely is the most important thing. Roundabouts give us the best opportunity. Drivers make mistakes, and roundabouts can reduce the impact of those mistakes. That’s something we can’t ignore, and that's why we really need people to start embracing roundabouts for the good that they can provide us.

Economically efficient

They are also good for the economy, because they help traffic flow more efficiently. Roundabouts offer better efficiency: they move cars better and more smoothly. Off-peak hours especially is when they really shine, because right now with a traffic signal or stop signs, you have to stop. There could be traffic, or they could be no traffic. You may stop for no reason. You're idling for no reason. With roundabouts you must slow down and look carefully, but if there is no traffic coming, you just slowly drive through the roundabout and you're on your way. There's no stopping and no idling. Roundabouts keep a community moving.

Some people express concerns about cost. In our experience, at the outset, costs generally work out about the same as they do for signal-based traffic intersections. Where the cost benefit lies, though, is in the reduction of long-term operating costs. With roundabouts, you are not paying for the electricity and maintenance of the traffic signal. You are not paying to fix the lights. And, back to the safety factor, if there's a power failure and street and traffic lights don't work, you can still go through a roundabout safely.

Clearing the air

Roundabouts have additional benefits in that they’re good for the environment, because they reduce greenhouse gas emissions. Remember all that idling that isn’t happening? There is potential to save huge volumes of fuel and reduce combustion emissions. One study from Kansas State University found the implementation of traffic circles reduced CO2 emissions in those locations by 16% to 59% and an 18% to 65% reduction in hydrocarbon emissions, depending on the time of day. That’s an incredible reduction in air pollutants by simply removing the stop and go of a traditional intersection.

Roundabouts are not going to solve all our traffic issues, but there are situations where, instead of building a traffic signal, instead of living with a four-way stop, and instead of building a four-lane road, roundabouts will give us the opportunity to provide road users with a safer intersection. The use of roundabouts offers our cities and towns a way to move traffic safely and efficiently while reducing emissions. We need to embrace their use, and consider them to be the primary alternative when building or renewing our infrastructure.